The present invention relates generally to an apparatus for mixing a liquid phase and a gaseous phase, and more particulaly to an apparatus of this type wherein no pressurized source of the gaseous phase is required.
There are instances in which a gaseous phase must be mixed with a liquid phase, for example to aerate the liquid phase, as is required in the aerobic growing of microorganism such as yeast, fungi and bacteria.
In most of the prior-art apparatus for this purpose the gaseous phase is admitted into the vessel containing the liquid phase, from a source of such gaseous phase under compression, for example from a blower or the like. This requires extra energy to operate the blower or the like and makes the equipment not only more expensive to produce but also more expensive to operate.
An attempt has therefore been made in the prior art to provide an apparatus of this type in which suction develops within the vessel accommodating the liquid phase, in order to thereby aspirate the gaseous phase without requiring that the gaseous phase be in pressurized condition. This has represented a step forward over the art preceding that last proposal, but experience has shown that in many instances the pressure head than can be obtained is not sufficient, so that the amount of gaseous phase that can be aspirated is inadequate to obtain optimum growth conditions for the microorganisms or the like.